1. Technical Field
The present invention relates to a technique of improving adhesiveness of a carbon-containing insulating film with other insulating films.
2. Related Art
In keeping with recent demands on higher speed operations of semiconductor elements, extensive researches have been made on altering the interlayer insulating film in multi-level interconnect layers from conventional silicon oxide film (specific dielectric constant is approximately k=3.9) to a low-dielectric-constant material film, aiming at decreasing parasitic interconnect capacitance. The low-dielectric-constant material referred to herein means any insulating material having a specific dielectric constant of 3.3 or smaller. Carbon-containing silicon oxide material is one of such low-dielectric constant material, wherein recent investigations have also been made on development of a porous material having micro-pores introduced in the film thereof, for the purpose of further lowering the dielectric constant. Use of these low-dielectric-constant material makes it possible to reduce cross talk among interconnections, and to realize high speed operations of the elements.
A problem has, however, arisen in that the interlayer insulating film composed of such low-dielectric-constant material is poor in adhesiveness with an etching stopper film typically made of SiCN or with a protective insulating film typically made of SiO2, which would result in peeling-off.
Japanese Laid-Open Patent Publication No. 2002-203899 discloses a technique of subjecting the insulating film to plasma treatment, to thereby improve the adhesiveness when copper was used as an interconnection material.
By the way, semiconductor devices are generally produced by cutting known as dicing using a cutting blade, so as to individualize the semiconductor chips. However, the individualization into the semiconductor chips by dicing has occasionally resulted in chipping of wafers. It has, therefore, been examined to carry out, as disclosed in Japanese Laid-Open Patent Publication No. 2004-179302, cutting and individualization typically by irradiating laser beam along the dicing line on a semiconductor wafer.
The conventional method described in Japanese Laid-Open Patent Publication No. 2002-203899, however, had to respectively subject copper and a barrier film in order to improve the adhesiveness, and consequently made the process more complicated.